Pipe coupling



FIG. 1 is a left side elevational view of a pipe coupling, showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevational view thereof; the rear elevational view being identical;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a perspective view thereof, from the top, front and left side; and,

FIG. 7 is a perspective view thereof, from the bottom, rear and right side. 

The ornamental design for a pipe coupling, as shown and described. 